oracle

login with your personal account

# su -

# su - oracle

list oracle instances

# cat /etc/oratab

# . oraenv

is instance up (no connected to idle instance)

# sqlplus / as sysdba

exit

another way to do it.

Connected to:

Oracle Database 11g Release 19.0.0.0.0 - 64bit Production


SQL> SELECT INSTANCE_NAME, STATUS, DATABASE_STATUS FROM V$INSTANCE;


INSTANCE_NAME STATUS       DATABASE_STATUS

----------------            ------------    -----------------

instance         OPEN       ACTIVE


SQL> exit

[oracle@mydbserver ~]$ ps -ef | grep pmon

oracle   17721     1  0  2023 ?        00:13:18 ora_pmon_someinstance

oracle   21931     1  0  2023 ?        00:59:38 ora_pmon_instance

oracle   30605 30079  0 09:34 pts/0    00:00:00 grep pmon

startup oracle instance

is oracle listener up and running (1521/tcp)

# lsnrctl status
if not running => lsnrctl start

does listener  listen any other  than  normal 1521  port
# netstat -anop | grep LISTEN | grep -v STREAM | grep tnslsnr

is disk space available

# df -h

how long machine has been up

# uptime

find alert.log location

# find $ORACLE_BASE -type f -name alert_$ORACLE_SID.log